The Northern New England Passenger Rail Authority, as established by Title 5, section 12004?F, subsection 16, is a body both corporate and politic in the State established for the general purpose of promoting passenger rail service as set forth in subchapter 1. It is declared that the purposes of this chapter are public and that the authority must be regarded as performing a governmental function in carrying out this chapter. [PL 2005, c. 312, §7 (AMD).]